The subject of the invention is related to an assembly for wet cleaning the combustion gases derived from combustion processes, especially the combustion of coal, coke and fuel oil. The assembly includes at least one device for dust extraction and at least one device for absorbing dust.
The gases produced in industrial processes from the combustion of coal, coke and fuel oil usually comprise many harmful components, mainly carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen oxides and dusts, which components may result in environmental degradation. Due to such reasons, there is a strong need for various methods and devices for dust extraction and for cleaning gases produced during combustion of coal coke and rock oil.
From Polish Patent Specification PL No 140 138 there is known an assembly for cleaning flue gases, especially from coal and coke combustion processes, characterized by feeding the combustion gases from a combustion room or changer into a cyclone-type dust collector and absorbing column, which are connected via a channel for hydraulic transport of dust and slag to a sedimentary tank. The sedimentary tank is equipped with a draw changer, connected via a pump with the absorbing column and via a pump with the channel for hydraulic transport. This assembly additionally comprises a preliming bath tank which may be automatically switched off.
The assembly as described above substantially functions properly in small industrial combustion rooms which are coke-fired, but its action is worse in combustion processes which are fine coal-fired, and worst in the case of big industrial combustion rooms. Additionally, damage to the cyclone collector causes additional lowering of the effectiveness of the assembly.
From Polish Patent Specification PL No 161 610 there is known a cleaning assembly which is free from the above mentioned drawbacks. In this assembly, in the flue gas path between a furnace and a chimney there is disposed a dust extracting device and a dust absorbing device. The dust extracting device consists of two tanks connected at their tops, one tank having a bevelled bottom, being partially filled with inert or active fluid and having near its bottom a pipe for delivering flue gases. This pipe is submerged in fluid, and above the pipe, two nets are disposed horizontally and in a spaced relation, the nets being submerged in fluid. The space between the nets is filled with loose, fibrous mineral bulk material. In the bottom of the tank, in the smallest place of the bevelled bottom thereof, there is placed a helical conveyor, having an end connected with a bucket conveyor. The second tank constitutes a bleeding tank and includes a vertical baffle in the form of two nets disposed in a spaced relation, and the space between these nets is also filled with loose, fibrous mineral, bulk material. Each of these devices, arranged in series, constitute a tank partially filled with active fluid reacting with specific components of the flue gases.
Above the pipe delivering the flue gases, submerged in active fluid and near the bottom thereof, two nets are disposed, arranged horizontally and in a spaced relation. Also, submerged in active fluid, the space between the nets is filled with fibrous mineral bulk material. Horizontal nets in both devices are slightly convergent, and between the last device for absorbing dust and the chimney, a vacuum producing device is disposed. Although this assembly functions successfully, it has been stated that the cleaning process runs slowly, and in the case of big combustion chamber installations, it does not operate satisfactorily.